1. Field of the Invention
The invention is directed to an acceleration pick-up device.
2. Description of Related Art
In known acceleration pick-up devices, the accelerative force acting on an inert body is monitored and measured. The inert body is maintained in its position of rest by an elastic member while the accelerative force, acting on the inert body, tends to move it out of its position of rest. Normally, this principle is not sufficient for precise measurements of acceleration values associated with very low oscillations or even constant acceleration. In navigation technique, particularly in space missions, it is desired that very low acceleration values are detected exactly and in the manner of absolute values. In this respect, a particular difficulty consists in that the measuring values of a calibrated acceleration pick-up device are valid for a limited time period only since the individual components of the measuring chain effect a drift. The spring constant of the elastic member can be considered as known so that the slope of the straight line indicating the ratio between the values of the measuring signal and of the existing acceleration is also known. The origin of the respective system of coordinates, however, is unknown. For calibrating the acceleration pick-up device, it would be suitable to know the absolute value of the acceleration of a pair of values consisting of the measured acceleration and the indicated value. Knowing said absolute value, however, requires a second acceleration pick-up device which is calibrated.
It is an object of the present invention to provide an acceleration pick-up device for measuring absolute values of acceleration which can be calibrated in a simple manner.